Chromium Picolinate Tablets
DEFINITION
Chromium Picolinate Tablets contain NLT 95.0% and NMT 125.0% of the labeled amount of chromium (Cr).
IDENTIFICATION
•  A. The Sample solution prepared as directed in the test for Strength gives a positive test for chromium, determined at 357.9 nm using the Instrumental conditions in the test for Content of Chromium.
STRENGTH
•  Content of Chromium
Standard stock solution A:  1000 µg/mL of chromium from potassium dichromate, previously dried at 120 for 4 h, in water. Store in a polyethylene bottle.
Standard stock solution B:  Transfer 1.0 mL of Standard stock solution A to a 100-mL volumetric flask, add 5.0 mL of 6 N hydrochloric acid, and dilute with water to volume to obtain a solution having a concentration of 10 µg/mL of chromium.
Standard solutions:  Dilute Standard stock solution B with 0.125 N hydrochloric acid to obtain concentrations of 1.0, 2.0, 3.0, and 4.0 µg/mL of chromium.
Sample solution:  Weigh and finely powder NLT 20 Tablets. Transfer a portion of the powder, equivalent to 5 Tablets, to a porcelain crucible, heat the crucible in a muffle furnace maintained at about 550 for 6–12 h, and cool. Add 60 mL of hydrochloric acid, and boil gently on a hot plate or steam bath for 30 min, intermittently rinsing the inner surface of the crucible with 6 N hydrochloric acid. Cool, and transfer the contents of the crucible to a 100-mL volumetric flask. Rinse the crucible with small portions of 6 N hydrochloric acid, and add the rinsings to the flask. Dilute with water to volume, mix, and filter, discarding the first 5 mL of the filtrate. Dilute this solution with 0.125 N hydrochloric acid to obtain a solution having a concentration of 2.5 µg/mL of chromium.
Instrumental conditions 
Mode:  Atomic absorption spectrophotometry
Lamp:  Chromium hollow-cathode
Flame:  Air–acetylene
Analytical wavelength:  357.9 nm (chromium emission line)
Blank:  0.125 N hydrochloric acid
Analysis 
Samples:  Standard solutions and Sample solution
Determine the absorbances of the Samples, using the Blank. From a linear regression equation, calculated using the absorbances of the Standard solutions versus the concentration, in µg/mL, of chromium, determine the concentration, C, in µg/mL, of chromium in the Sample solution.
Calculate the percentage of the labeled amount of chromium (Cr) in the portion of Tablets taken:
Result = (C/CU) × 100
C== determined concentration of chromium in the Sample solution (µg/mL)
CU== nominal concentration of chromium in the Sample solution (µg/mL)
Acceptance criteria:  95.0%–125.0%
PERFORMANCE TESTS
•  Disintegration and Dissolution of Dietary Supplements 2040: Meet the requirements for Disintegration
•  Weight Variation of Dietary Supplements 2091: Meet the requirements
ADDITIONAL REQUIREMENTS
•  Packaging and Storage: Preserve in well-closed containers, and store at controlled room temperature.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Natalia Davydova
Scientific Liaison
1-301-816-8328
(DS2010) Monographs - Dietary Supplements
USP35–NF30 Page 1251
Pharmacopeial Forum: Volume No. 30(5) Page 1664